Viral diseases inflict man, plants, insects, and animals. The prevention and control of viral diseases have important health and economic implications.
Viral diseases contribute to inflictions in humans including common colds, herpes and cancer and the importance of their control is obvious. Also important is control of viral diseases in animals for economic reasons as well as the ability of such animals to become virus reservoirs or carriers which facilitate the spreading of viral diseases to humans. Viral plant diseases have been known to have a disruptive effect on the cultivation of fruit trees, tobacco, and various vegetables. Insect viral diseases are also of interest because of the insects' ability to transfer viral diseases to humans.
The prevention and control of viral diseases is thus of prime importance to man and considerable research has been devoted to antiviral measures. Certain methods and chemical compositions have been developed which aid in inhibiting, controlling or destroying viruses but new methods and antiviral chemical compositions are needed.
U.S. Pat. Nos. 4,162,308 and 4,162,309 to Calvin and Ellis describe that water soluble extracts from marine red algae have been found to be effective to inhibit the growth of certain herpes viruses.
U.S. Pat. No. 4,162,308 describes water soluble extracts from marine red algae selected from a group consisting of Turnerella mertensiana, Schizymenia epiphytica, Turnerella pennyi and mixtures thereof as effective to inhibit the growth of herpes simplex virus, type 1 and type 2, and herpes zoster, and to relieve the pain caused by infection attributable to such viruses.
U.S. Pat. No. 4,162,309 describes the use of water soluble extracts from marine red algae selected from a group consisting of Neodilsea americana and Neodilsea integra and mixtures thereof to inhibit the growth of herpes simplex virus, type 1 and type 2, and herpes zoster, and to relieve the pain caused by infection attributable to such viruses. The entire disclosures of U.S. Pat. Nos. 4,162,308 and 4,162,309 are hereby incorporated herein by reference.
Crews et al in "Bio-Active Monoterpenes from Red Seaweeds", Phytochemistry Vol. 23 No. 7 Pp. 1449-1451, Pergamon Press Ltd., Great Britain, 1984, describe the bioactivity of seaweed derived monoterpenes. Crews et al disclose halogenated monoterpenes which are extracted from red algae Chondrococcus hornemanni with methylene chloride. The halogenated monoterpenes were shown to be bioactive in various applications and biotoxic against insects.
In addition to the water soluble red algae extractions described in the above noted U.S. Patent applications to Calvin and Ellis and the halogenated monoterpenes of Crews et al other compounds have been isolated from red algae and marine organisms known as sea hares which are mollusks which diet on red algae. These compounds include halogenated chamigrenes and have been described in various literature references including P. J. Scheuer, Ed. Marine Natural Products Volume 1 (Martin) and Volume 5 (Erickson) Academic Press, 1978, 1983, the entire disclosure of this reference is hereby incorporated herein by reference.
The present inventors have also filed patent applications relating to compounds prepared from red algae and extracts of sea hares, which diet on red algae, comprising certain halogenated chamigrenes which show antiviral activity, i.e., U.S. patent application Ser. No. 682,896 filed Dec. 18, 1984 and certain cyclohexadienone compounds which show antiviral and antitumor activity i.e., U.S. patent application Ser. Nos. 682,278 and 744,620 filed Dec. 17, 1984 and June 14, 1985, respectively. The entire disclosure of these three co-pending applications is hereby incorporated herein by reference.
A further co-pending application of the present inventors filed concurrently herewith relates to compounds prepared from red algae and extracts of sea hares, which diet on red algae, comprising certain halogenated chamigrenes which show antitumor activity.
Prevention, control of the growth and regression of tumors in mammals is also of importance to man. Considerable research has been devoted to oncology and antitumor measures. The term tumor refers to abnormal masses of new tissue growth which is discordant with the economy of the tissue of origin or the host's body as a whole. Tumors are common in a variety of mammals and the prevention, control of the growth and regression of tumors in mammals is important to man.
Tumors inflict mammals and man with a variety of disorders and conditions including various forms of cancer and resultant cancerous cachexia. Cancerous cachexia refers to the symptomatic discomfort that accompanies the infliction of a mammal with a tumor. These systems include weakened condition of the inflicted mammal as evidenced by, for example, weight loss. The seriousness of cancer is well known, e.g., cancer is second only to heart and vascular diseases as a cause of death in man.
Considerable research and resources have been devoted to oncology and antitumor measures including chemotherapy. While certain methods and chemical compositions have been developed which aid in inhibiting, remitting or controlling the growth of tumors new methods and antitumor chemical compositions are needed.
It has now been found that certain cyclohexadienone compounds derived from extracts of red algae possess useful antiviral and antitumor activity.